CN111681995B

CN111681995B - Thyristor element, thyristor element assembly structure and soft starter

Info

Publication number: CN111681995B
Application number: CN202010355028.2A
Authority: CN
Inventors: 郭金童; 操国宏; 曾文彬; 孙文伟; 刘应; 董超; 邓超; 陈本龙; 唐豹
Original assignee: Zhuzhou CRRC Times Semiconductor Co Ltd
Current assignee: Zhuzhou CRRC Times Semiconductor Co Ltd
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2022-09-09
Anticipated expiration: 2040-04-29
Also published as: CN111681995A; WO2021218963A1; EP4145502A1

Abstract

The application provides a thyristor component, thyristor component assembly structure and soft starter, this thyristor component include gate pole subassembly and chip package subassembly, and the blind hole of at least partial fixed joint gate pole subassembly is seted up to the chip package subassembly, the chip in the axis perpendicular to chip package subassembly of blind hole, and the gate pole subassembly includes: a gate pin extending from an interior of the gate assembly and abutting a chip gate of the chip; and a terminal lug extending out of the top of the gate assembly for connecting the gate pin and the lead wire. The thyristor element assembly structure includes a first heat sink, a second heat sink, and a thyristor element sandwiched therebetween. The first heat sink and the second heat sink are connected by an insulating fastener. The disc spring group of the insulating fastener is sleeved outside the insulating sleeve and positioned between the first radiator and the insulating sleeve. By utilizing the thyristor element, welding can be avoided, the assembly difficulty can be reduced, the service life of the soft starter can be prolonged, and the cost of the soft starter can be reduced.

Description

Thyristor element, thyristor element assembly structure and soft starter

Technical Field

The invention relates to the technical field of soft starting of motors, in particular to a thyristor element, a thyristor element assembling structure and a soft starter.

Background

When the motor is in soft start, the output voltage of the thyristor in the soft starter is gradually increased, the motor is gradually accelerated until the thyristor is fully conducted, and the voltage of the motor reaches the rated working voltage, so that the smooth start of the motor is realized, and the starting current trip can be avoided.

The motor with the power below 100kW generally adopts a single-side heat dissipation thyristor element assembly structure shown in figure 1 during soft start. The thyristor component assembly structure comprises a metal bottom plate 1, an insulating heat conducting plate 2, a silicon chip 3 and a radiator 4 positioned on one side of the silicon chip 3. Because the heat dissipation capacity of the thyristor element assembly structure is limited, the soft start of a motor with the power of more than 100kW cannot be realized.

For a motor having a power of 100kW or more, for soft start, a thyristor element mounting structure such as that shown in fig. 2 is commonly used. The thyristor component assembly structure comprises two radiators 4 which are respectively positioned on two sides of a thyristor component 5, so that the heat dissipation capacity of the thyristor component assembly structure is improved. Fig. 3 shows a schematic cross-sectional view of the thyristor element 5 in fig. 2.

In the prior art, as shown in fig. 3, the gate component 6 of the thyristor device 5 is packaged inside the chip package 7, and the inner lead 11 and the outer lead 12 are connected by the lead tube 9 penetrating through the ceramic sidewall 8 to connect the gate of the thyristor chip to the outside, wherein the outer lead 12 and the lead tube 9 need to be connected by welding. The fatigue resistance of the welding is weak, which is not favorable for improving the service life of the thyristor element 5. Moreover, the thyristor element 5 in the prior art has a complex structure, a difficult assembly process and a high production cost, and is not favorable for popularization and application of the thyristor element 5.

Disclosure of Invention

To solve the problems in the prior art, the application provides a thyristor element, a thyristor element assembling structure and a soft starter. Because the novel gate pole component is adopted, welding is not used, and the service life of the thyristor element is prolonged. Meanwhile, the structure of the thyristor element is simplified, the assembly process difficulty and the production cost are reduced, and the popularization and the application of the thyristor element are facilitated.

In a first aspect, the present invention provides a thyristor element comprising a gate element and a die package, the die package defining a blind hole at least partially fixedly coupled to the gate element, the blind hole having an axis perpendicular to a die in the die package, the gate element comprising: a gate pin extending from the interior of the gate assembly and having a bottom abutting a chip gate of the chip; a terminal tab extending from the top of the gate assembly for connecting the gate pin and lead wire. The thyristor element can avoid welding and lead from penetrating the side wall of the chip packaging assembly, is favorable for prolonging the service life of the thyristor element, is also favorable for reducing the production cost of the thyristor element, and is favorable for reducing the volume of the thyristor element.

In one embodiment of the first aspect, the gate assembly comprises: the gate pole needle comprises a needle body and an elastic part which are integrally formed, and the needle body is abutted against the gate pole of the chip; the first end of the lug plate is embedded into the elastic piece, and the second end of the lug plate is provided with a through hole for fixing the lead; the first gate pole piece is penetrated by the needle body and abutted with the gate pole of the chip; and the second gate piece is sleeved outside the first gate piece and fixedly jointed in the blind hole of the chip packaging assembly so as to fixedly joint the gate assembly and the chip packaging assembly. The gate pole component in the embodiment has the advantages of simple manufacturing process, long service life, stable performance, low cost and the like, and is favorable for popularization and application of the gate pole component.

In one embodiment of the first aspect, the outer wall of the second gate member is at least partially threaded with the side wall of the blind hole of the chip package assembly. Through this embodiment, can be convenient fixed connection gate pole subassembly and chip package subassembly.

In one embodiment of the first aspect, the second gate member is in interference fit with the first gate member to form a cavity for accommodating the elastic member in a compressed state, and the lug passes through the second gate member to be connected with the gate needle. Through this embodiment, the gate needle is in contact with the gate of the chip, thereby facilitating the stable transmission of signals.

In one embodiment of the first aspect, the diameter of the cavity is 0.1-0.3mm larger than the diameter of the resilient member. Through this embodiment, can guarantee that the elastic component can not bending deformation in the in-process of compression, be favorable to the stable transmission of signal.

In one embodiment of the first aspect, the blind via is located in a middle portion of the chip package assembly. Through this embodiment, be favorable to stress evenly distributed, avoid local strain to be favorable to improving the life of thyristor component.

In one embodiment of the first aspect, the chip package assembly includes a first package housing and a second package housing, the first package housing and the second package housing enclose a package cavity, and an anode molybdenum sheet, the chip, a cathode molybdenum sheet, and a silver gasket are stacked in the package cavity in sequence, wherein the anode molybdenum sheet is in contact with the first package housing, and the silver gasket is in contact with the second package housing; the gate needle penetrates through the silver gasket and the through hole in the cathode molybdenum sheet to abut against the gate of the chip. The chip packaging assembly in the embodiment has the advantages of simple manufacturing process, long service life, stable performance, low cost and the like, and is favorable for popularization and application of the chip packaging assembly.

In one embodiment of the first aspect, the first package housing includes an anode copper block and an anode plastic housing surrounding the anode copper block, the second package housing includes a cathode copper block and a cathode plastic housing surrounding the cathode copper block, and the blind hole is opened in the middle of the cathode copper block. By the embodiment, the weight of the thyristor element is favorably reduced, and the sealing cost is favorably reduced.

In one embodiment of the first aspect, the first package housing and the second package housing are both formed using a metal insert injection molding process.

In one embodiment of the first aspect, the chip package assembly packages the chip by using a solid sealing medium, and the first package housing is provided with a glue injection opening. By this embodiment, due to the use of a solid sealing medium, the cost of the thyristor element can be greatly reduced compared to filling with nitrogen.

In one embodiment of the first aspect, the solid sealing medium is silica gel. With this embodiment, the packaging cost can be further reduced.

In one embodiment of the first aspect, the silica gel has a viscosity of between 500 and 800mpa.s when in the liquid state; after the silica gel is cured, the dielectric strength of the silica gel is 12 kV/mm.

In a second aspect, the present invention also provides a thyristor component assembly structure comprising a first heat sink, a second heat sink and the thyristor component described above sandwiched between the first heat sink and the second heat sink. Through this embodiment, need not to adopt welding and lead wire need not to run through the lateral wall of chip package subassembly, be favorable to improving thyristor component assembly structure's life, also be favorable to reducing thyristor component assembly structure's manufacturing cost, and be favorable to reducing thyristor component assembly structure's volume.

In one embodiment of the second aspect, the first heat sink and the second heat sink are fixedly connected by four insulating fasteners, the insulating fasteners comprising: the screw rod penetrates through the first radiator and is in threaded fit with the threaded hole of the second radiator; the insulating sleeve is sleeved on the screw rod; the disc spring group is sleeved outside the insulating sleeve and positioned between the first radiator and the insulating sleeve; and the gasket is sleeved on the insulating sleeve and arranged at two ends of the disc spring group. Through this embodiment, can avoid using levelling device, and can guarantee pressure evenly distributed. Moreover, the insulating fastener in this embodiment can ensure that the first heat sink and the second heat sink are in an electrically isolated state while fixing the first heat sink and the second heat sink, thereby avoiding occurrence of a short circuit.

In one embodiment of the second aspect, the insulating sleeve is a one-piece sleeve, and the insulating sleeve includes a first tube and a second tube that are communicated with each other, the first tube has a diameter larger than that of the second tube, the first tube is used for accommodating a head of the screw, and the second tube is used for accommodating a part of a main body of the screw and extends from the first radiator to the second radiator. With this embodiment, a soft starter employing an integral bushing can withstand voltages up to 6500 v.

In one embodiment of the second aspect, the insulation sleeve includes a first tube and a second tube that are separated from each other, the first tube being located between the main body of the screw and the first heat sink, and the second tube being located between the main body of the screw and the second heat sink. By this embodiment, the cost of the insulating fastener can be saved.

In one embodiment of the second aspect, the insulating sleeve is made of a material having a relative tracking index of less than or equal to 400. By this embodiment, it is advantageous to ensure safe use of the thyristor element assembly structure.

In one embodiment of the second aspect, the thyristor element assembly structure includes two antiparallel thyristor elements and two first heat sinks, the first heat sinks corresponding to the thyristor elements one to one. Through this embodiment, two first radiators have undertaken the effect of connecting two thyristor components as a whole, need not to use external copper bar to connect, can realize anti-parallelly connected, can reduce material cost and reduce thyristor component assembly structure's volume, are favorable to soft starter's miniaturization to improve soft starter's market competition.

In one embodiment of the second aspect, two of the first heat sinks form an integral heat sink with stress isolation slots opened therebetween. By this embodiment, it is advantageous to avoid pressure interference.

In one embodiment of the second aspect, the first heat sink includes a first base and a plurality of first fins, and the stress separation groove is disposed between two first bases; the second heat sink includes a second base and a plurality of second fins. Through this embodiment, be favorable to improving the heat-sinking capability of radiator.

In a third aspect, the present invention also provides a soft starter comprising the above thyristor element assembly structure. Through this embodiment, soft starter has adopted the thyristor component assembly structure who has above-mentioned thyristor component, need not to adopt welding and lead wire need not to run through the lateral wall of chip package subassembly, is favorable to improving soft starter's life, also is favorable to reducing soft starter's manufacturing cost, and is favorable to soft starter's miniaturization to be favorable to this soft starter to obtain market acceptance.

The application provides a thyristor component, thyristor component assembly structure and soft starter compares in prior art, has following beneficial effect:

1. because a welding connection structure with weak fatigue resistance is not needed, structural instability caused by welding can be avoided, and the service life of the soft starter is prolonged.

2. Because a lead does not need to penetrate through the ceramic side wall of the chip packaging assembly, the production cost of the soft starter is reduced.

3. The thyristor element has the advantages of simple structure, low assembly process difficulty and low production cost, and is favorable for popularization and application.

4. Due to the adoption of the solid sealing medium, compared with the method of filling nitrogen, the cost of the thyristor element can be greatly reduced.

The features mentioned above can be combined in various suitable ways or replaced by equivalent features as long as the object of the invention is achieved.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings, in which:

fig. 1 shows a schematic cross-sectional view of a thyristor component mounting structure according to the prior art;

fig. 2 shows a schematic cross-sectional view of another thyristor component mounting structure according to the prior art;

fig. 3 shows a schematic cross-sectional view of the thyristor component of fig. 2;

fig. 4 shows an exploded schematic view of a thyristor component according to an embodiment of the invention;

fig. 5 shows a schematic perspective view of a thyristor element according to an embodiment of the invention;

FIG. 6 is a schematic diagram of a gate assembly according to one embodiment of the present invention;

FIG. 7 shows a schematic cross-sectional view of a gate assembly according to an embodiment of the present invention;

fig. 8 shows a schematic cross-sectional view of a thyristor element according to an embodiment of the invention;

fig. 9 shows a perspective view of a thyristor component mounting structure according to an embodiment of the invention;

fig. 10 shows a schematic cross-sectional view of a thyristor component mounting structure according to an embodiment of the invention;

FIG. 11 shows a cross-sectional view of an insulating fastener according to an embodiment of the invention;

fig. 12 shows a schematic cross-sectional view of a thyristor component mounting structure according to an embodiment of the invention and shows the lead wires;

FIG. 13 shows a partial enlarged view of area A of FIG. 12;

fig. 14 shows a circuit topology of a thyristor component mounting structure according to an embodiment of the invention.

List of reference numerals:

1-a metal base plate; 2-insulating heat conducting plate; 3-silicon chip; 4-a radiator; 5-a thyristor element; a 6-gate assembly; 7-a chip package assembly; 8-ceramic sidewalls; 9-a lead tube; 10-an insulating fastener; 11-inner leads; 12-outer leads; 20-a lead; 50-a first heat sink; 60-a chip package assembly; 70-a second heat sink; an 80-gate assembly; 101-disc spring group; 102-a screw; 103-an insulating sleeve; 104-a shim; 501-a first substrate; 502-a first fin; 601-a second package housing; 602-silver shim; 603-cathode molybdenum sheet; 604-a chip; 605-anode molybdenum sheet; 606-a first package housing; 607-Red glue; 608-blind hole; 701-a first substrate; 702-a second fin; 801-lugs; 802-second gate member; 803-menpole needle; 804 — first gate pole piece; 5011-stress separation groove; 6011-cathode copper block; 6012-cathode plastic enclosure; 6061-anode copper block; 6062-anodic plastic housing.

In the drawings, like parts are provided with like reference numerals. The drawings are not to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 4-8, the present embodiment provides a thyristor device comprising a gate assembly 80 and a semiconductor package assembly 60, the semiconductor package assembly 60 defining a blind hole 608 at least partially fixedly coupled to the gate assembly 80, an axis of the blind hole 608 being perpendicular to a semiconductor die 604 of the semiconductor package assembly 60, the gate assembly 80 comprising: a gate pin 803 extending from the interior of the gate assembly 80 and having a bottom abutting the chip gate of the chip 604; a lug 801 extending out of the top of the gate assembly 80 for connecting the gate pin 803 to the lead wire 20.

As shown in fig. 2 and 3, in the prior art, as shown in fig. 3, the gate component 6 of the thyristor device 5 is packaged inside the package 7 of the thyristor device, and the lead tube 9 penetrating through the ceramic sidewall 8 is used to connect the inner lead 11 and the outer lead 12 to connect the gate of the thyristor chip to the outside, wherein the outer lead 12 and the lead tube 9 need to be connected by soldering. The fatigue resistance of the welding is weak, which is not favorable for improving the service life of the thyristor element 5. Moreover, the thyristor element 5 in the prior art has a complex structure, a difficult assembly process and a high production cost, and is not favorable for popularization and application of the thyristor element 5.

To avoid soldering and also to avoid the leads 20 from penetrating the sidewalls of the semiconductor package 60, the present embodiment employs a gate assembly 80 as shown in fig. 6 and 7. The gate assembly 80 includes a gate pin 803 and a terminal plate 801, wherein the gate pin 803 is directly against the gate of the chip 604, and the lead 20 is fixedly connected to the terminal plate 801, thereby achieving the purpose of connecting the lead 20 to the gate of the chip.

Specifically, a gate pin 803 extending from the interior of the gate assembly 80 and having its bottom abutting the chip gate of the chip 604; a lug 801 extending out of the top of the gate assembly 80 for connecting the gate pin 803 to the lead wire 20. The top of the gate element 80 is the end of the gate element 80 that extends out of the blind hole 608 and opens onto the outer surface of the semiconductor package 60, and the bottom of the gate pin 803 is the end of the gate pin 803 that opens onto the outer surface of the semiconductor package 60 away from the blind hole 608.

The gate member 80 is disposed in a blind hole 608 on the semiconductor package 60, the axis of the blind hole 608 being perpendicular to the semiconductor die 604 in the semiconductor package 60, i.e., the axis of the gate member 80 is disposed perpendicular to the semiconductor die 604. This arrangement is simpler than the lead 20 that uses the lead sleeve and other structures to penetrate the sidewall of the semiconductor package 60, because the sidewall of the semiconductor package 60 in the prior art is mostly ceramic, and the blind hole 608 of this embodiment is disposed on the cathode copper block 6011.

Furthermore, the thyristor element has a simple structure, which is advantageous for miniaturization.

By using the above structure of the present embodiment, the connecting lead 20 and the gate of the chip do not need to be welded, and the lead 20 does not need to penetrate through the sidewall of the package assembly 60, which is beneficial to improving the service life of the thyristor, reducing the manufacturing cost of the thyristor, and reducing the volume of the thyristor.

As shown in fig. 6 to 8, the gate assembly 80 of the present embodiment optionally includes: a gate pin 803 including a pin body and an elastic member integrally formed, the pin body abutting against the gate of the chip; a lug 801 having a first end in which the elastic member is inserted and a second end provided with a through hole for fixing the lead 20; a first gate pole piece 804, wherein the needle body passes through the first gate pole piece 804 and abuts against the gate pole of the chip; the second gate member 802 is disposed over the first gate member 804 and is fixedly coupled to the blind hole 608 of the semiconductor package 60 to fixedly couple the gate assembly 80 and the semiconductor package 60.

The gate electrode assembly 80 is connected with the lead wire 20 and the gate electrode chip 604, has the advantages of simple manufacturing process, long service life, stable performance, low cost and the like, and is beneficial to popularization and application of the gate electrode assembly 80.

Alternatively, the diameter of gate needle 803 may be between 0.2-1.0 mm. When the gate needle 803 is compressed to 1/2, its spring force is 3N or more. First, the second gate member 802 and the tab 801 are integrated by a metal insert molding process. In assembling the gate assembly 80, the gate pole pin 803 is inserted into a through hole in the middle of the first gate pole piece 804, and then the first gate pole piece 804 and the second gate pole piece 802 to which the lug 801 is fixed are coupled by rotation.

As shown in fig. 8, optionally, the outer wall of the second gate piece 802 of the present embodiment is at least partially screwed with the sidewall of the blind hole 608 of the chip package assembly 60.

Through the threaded connection between the outer wall of the second gate member 802 and the sidewall of the blind hole 608 of the semiconductor package 60, the gate member 80 can be fixedly connected to the semiconductor package 60, and the semiconductor package has a good sealing effect to prevent the chip 604 from being oxidized. In addition, the threaded connection facilitates rapid assembly of the gate assembly 80 and the chip package assembly 60, and the threads are easy to process, thereby facilitating cost reduction and facilitating popularization and application of the thyristor element.

During mounting, the torque is optionally controlled to 0.5-1.5Nm, thereby tightening the gate assembly 80 and the semiconductor package assembly 60.

As shown in fig. 7, optionally, the second gate pole piece 802 of this embodiment is in interference fit with the first gate pole piece 804 to form a cavity for accommodating the elastic piece in a compressed state, and the lug 801 passes through the second gate pole piece 802 to be connected with the gate pole pin 803.

The interference fit of the second gate piece 802 with the first gate piece 804 facilitates sealing and thus avoids oxidation of the chip 604. In order to contact the gate pin 803 with the gate of the chip and thus ensure stable signal transmission, the length of the gate pin 803 needs to be reduced to 1/2-3/4 when the first gate piece 804 and the second gate piece 802 are connected.

Optionally, the diameter of the cavity of the present embodiment is 0.1-0.3mm larger than the diameter of the elastic member.

Because the diameter of the cavity is 0.1-0.3mm larger than that of the elastic part, the elastic part can not be bent and deformed in the compression process, and stable transmission of signals is facilitated.

As shown in fig. 4, the blind hole 608 of the present embodiment is optionally located in the middle of the chip package assembly 60.

The blind hole 608 is located in the middle of the chip package assembly 60, i.e., the gate assembly 80 is located in the middle of the chip package assembly 60, which is beneficial to uniform stress distribution and avoiding local strain, thereby being beneficial to improving the service life of the thyristor element.

As shown in fig. 8, optionally, the chip package assembly 60 of the present embodiment includes a first package housing 606 and a second package housing 601, the first package housing 606 and the second package housing 601 enclose a package cavity, and an anode molybdenum sheet 605, a chip 604, a cathode molybdenum sheet 603, and a silver gasket 602 are stacked in the package cavity in sequence, wherein the anode molybdenum sheet 605 is in contact with the first package housing 606, and the silver gasket 602 is in contact with the second package housing 601; the gate pin 803 passes through the through holes on the silver shim 602 and the cathode molybdenum plate 603 against the chip gate.

Because the thermal expansion coefficients of the anode copper block 6061 of the first package housing 606 and the cathode copper block 6011 of the second package housing 601 are different from those of the silicon chip 604, in order to avoid abrasion of the aluminum layer of the chip 604, the anode molybdenum sheet 605 and the cathode molybdenum sheet 603 are disposed on two sides of the chip 604.

The silver gasket 602 has good ductility, so that the silver gasket 602 is sandwiched between the cathode molybdenum sheet 603 with different flatness and the cathode copper block 6011 of the second package housing 601 as a buffer layer, which is beneficial to the stable operation of the thyristor component.

Optionally, a first package housing 606, an anode molybdenum sheet 605, a chip 604, a cathode molybdenum sheet 603, a silver gasket 602, and a second package housing 601 are stacked in sequence for assembly. After assembly, the resistance between the gate assembly 80 and the cathode copper 6011 of the second package housing 601 should be between 5 Ω and 40 Ω.

The embodiment is suitable for the full-pressure chip with double-sided aluminum evaporation, and when the chip is a sintered chip, only the cathode aluminum evaporation is adopted, so that an anode molybdenum sheet can be omitted.

The package cavity of the chip package assembly 60 is in communication with the cavity of the gate assembly 80. The gate pin 803 passes through the through holes on the silver shim 602 and the cathode molybdenum plate 603 to abut the chip gate.

The chip package assembly 60 in this embodiment has the advantages of simple manufacturing process, long service life, stable performance, low cost, and the like, and is beneficial to popularization and application of the chip package assembly 60.

As shown in fig. 8, optionally, the first package housing 606 of this embodiment includes an anode copper block 6061 and an anode plastic housing 6062 surrounding the anode copper block 6061, the second package housing 601 includes a cathode copper block 6011 and a cathode plastic housing 6012 surrounding the cathode copper block 6011, and the blind hole 608 is opened in the middle of the cathode copper block 6011.

The use of a plastic housing is advantageous for weight reduction and for reducing the cost of the seal. This is because when the first and

second package housings

606 and 601 are both copper, they can only be sealed using welding or even cold pressure welding processes. When the cold welding process is adopted, the requirement on equipment is high, the packaging process is complex, the packaging material must adopt oxygen-free copper, and the cost is overhigh. Because the anode copper block 6061 and the anode plastic shell 6062 are of an integrated structure and the cathode copper block 6011 and the cathode plastic shell 6012 are of an integrated structure, the encapsulation cavity between the first encapsulation shell 606 and the second encapsulation shell 601 can be formed only by sealing the anode plastic shell 6062 and the cathode plastic shell 6012. In contrast, the sealing process between the anode plastic casing 6062 and the cathode plastic casing 6012 is simple and low cost.

The blind hole 608 is formed in the middle of the cathode copper block 6011, that is, the gate module 80 is located in the middle of the cathode copper block 6011, so as to facilitate uniform distribution of stress and avoid local strain, thereby facilitating improvement of the service life of the thyristor element.

Optionally, the first package housing 606 and the second package housing 601 of the present embodiment are both formed by a metal insert injection molding process.

The metal piece injection molding process is a widely used mature process, and is beneficial to reducing the manufacturing cost of the first package housing 606 and the second package housing 601.

Optionally, the chip package assembly 60 of the present embodiment uses a solid sealing medium to package the chip 604, and the first package housing 606 is provided with a glue injection opening.

The liquid sealing medium can enter the packaging cavity through the glue injection port, and the liquid sealing medium becomes solid after solidification. Optionally, the liquid sealing medium should immerse the cathode molybdenum sheet 603 to avoid oxidation of the wafer 604.

Alternatively, the structure may be filled with nitrogen, but the sealing performance is more demanding, and leak detection testing is required after packaging. In order to ensure the sealing performance, a pressure welding process is generally adopted for packaging, the process is complex, and the equipment maintenance cost is high. In order to use the bonding process, it is also necessary to use the first package housing 606 and the second package housing 601 made of oxygen-free copper, which is much more costly than red copper. Furthermore, nitrogen is used as a gas, and storage and transportation thereof also increase the cost of the product.

Because the solid sealing medium is adopted, the cathode copper block 6011 and the anode copper block 6061 can be made of red copper, a pressure welding process is not needed, leak detection is not needed after sealing, and the cost of a product can be greatly reduced.

Optionally, the solid sealing medium of this embodiment is silica gel.

Silica gel is used as a common industrial material, and is convenient to use and low in cost. And silica gel is used as a solid sealing medium, so that the cost is reduced.

Optionally, when the silica gel of the embodiment is in a liquid state, the viscosity thereof is between 500-800 mpa.s; after the silica gel is solidified, the dielectric strength is 12 kV/mm.

The viscosity of the silica gel is too high, so that the silica gel is not favorable for entering narrow and tiny gaps; the viscosity of the silica gel is too low to facilitate the subsequent curing, so the viscosity of the silica gel needs to be controlled between 500-800 mPa.s.

The larger the dielectric strength of the silica gel is, the less likely to be broken down, which is more beneficial to improving the high voltage resistance of the thyristor element. However, when the dielectric strength of the silica gel exceeds a certain value, the cost thereof is greatly increased. Therefore, the dielectric strength of the cured silica gel can meet the design requirement when reaching 12 kV/mm.

Alternatively, the liquid silica gel is formed by mixing two-component silica gel 1: 1.

In addition, the liquid silicone gel used is not chemically reactive with the red gel 607 used to protect the chip 604. To avoid chemical reactions, the pre-selected silica gel needs to be tested before the first encapsulation. During testing, the chip 604 is first immersed in the preselected liquid silicone rubber, and then the liquid silicone rubber is cured and observed after curing. If the edge of the red glue 607 is observed to have a flocculent or liquid, it can be determined that the red glue 607 has reacted with the tested silica gel, and the tested silica gel cannot be used.

Optionally, the main parameters of the silica gel encapsulation process are: the vacuum degree of the cavity is-0.06-0.08 MPa; the vacuum defoaming time is 5-8 min; the curing temperature is 130 +/-5 ℃; the curing time was 60 min.

As shown in fig. 9, the present embodiment also provides a thyristor element assembly structure including a first heat sink 50, a second heat sink 70, and the above-described thyristor element sandwiched between the first heat sink 50 and the second heat sink 70.

Compared with the radiator arranged on only one side of the thyristor element, the thyristor element assembling structure is beneficial to improving the heat dissipation capacity of the thyristor element assembling structure, so that the thyristor element assembling structure is suitable for soft start of a motor with power of more than 100 kW.

The thyristor component assembly structure of the present embodiment adopts the above thyristor component, which can avoid welding and prevent the lead 20 from penetrating the side wall of the chip package assembly 60, thereby being beneficial to improving the service life of the thyristor component assembly structure, being beneficial to reducing the production and use costs of the thyristor component assembly structure, and being beneficial to reducing the volume of the thyristor component assembly structure.

In order to meet the requirements of different working conditions on creepage distance, the vertical distance between the first radiator 50 and the second radiator 70 is a critical dimension for determining whether the assembly is qualified or not.

As shown in fig. 9 to 11, optionally, the first heat sink 50 and the second heat sink 70 of the present embodiment are fixedly connected by four insulating fasteners 10, and the insulating fasteners 10 include: a screw 102 which is threaded through the first heat sink 50 and is engaged with the threaded hole of the second heat sink 70; an insulating sleeve 103 sleeved on the screw 102; the disc spring group 101 is sleeved outside the insulating sleeve 103 and is positioned between the first radiator 50 and the insulating sleeve 103; and the gaskets 104 are sleeved on the insulating sleeve 103 and arranged at two ends of the disc spring group 101.

The insulating fastener 10 in the present embodiment can secure the first heat sink 50 and the second heat sink 70 in an electrically isolated state while fixing the first heat sink 50 and the second heat sink 70, thereby avoiding occurrence of a short circuit.

The screw 102 serves to fixedly connect the first heat sink 50 and the second heat sink 70, and the screw 102 includes a head and a rod-shaped body. The rod-shaped body extends from the first heat sink 50 to the second heat sink 70 and is screw-fitted with the second heat sink 70. Optionally, the head of the screw 102 is provided with an inner hexagonal counterbore to make the installation process more time-saving and labor-saving. The present embodiment does not limit the strength of the screw thread of the second heat sink 70. Alternatively, in order to adjust the thread strength, a wire thread insert assembling process may be applied. When the steel wire thread insert is used, lubricating oil can be coated to avoid the phenomena of thread adhesion, thread seizure and the like.

The insulating sleeve 103 fitted over the screw 102 is mainly used to electrically isolate the first heat sink 50 from the second heat sink 70.

As shown in fig. 9 to 11, the disc spring set 101 is sleeved outside the insulating sleeve 103, so that the diameter of the disc spring is not limited by the inner diameter of the insulating sleeve 103, and the size of the disc spring can be freely adjusted according to the required disc spring load, thereby facilitating optimization of the ratio of the number of the disc springs to the diameter of the disc spring. The disc spring group 101 functions to absorb shock, thereby improving the service life of the thyristor element assembly structure.

Alternatively, the present embodiment discloses a possible combination of disc spring sets 101 according to the requirements of deformation and load. According to the combination mode, a plurality of disc springs are divided into two groups, all the disc springs in each disc spring group are overlapped (connected in parallel), and then the two groups are combined (connected in series). Alternatively, each disc spring subgroup is composed of five stacked disc springs, i.e. each insulating fastener 10 comprises ten disc springs.

Optionally, the size of the disc spring is designed to take into account the axial expansion of the relevant parts after heating. Optionally, the maximum operating temperature of the thyristor component assembly structure of the present embodiment is 130 ℃ and the normal temperature is 30 ℃. As shown in fig. 10, the first base 501 of the first heat sink 50 has a thickness h ₁ The working length of the screw 102 is L, and the distance between the first tube and the second tube of the insulating sleeve 103 is h ₃ . According to the following formula for heat distortion:

σ＝ρ×H×ΔT

when the material of the first substrate 501 is 6 series aluminum alloy (density: 23.8X 10) ^-6 /° c), the material of the screw 102 is carbon steel (density: 11.5X 10 ^-6 /° c), one can obtain:

axial deformation σ of the first substrate 501 _h1 Is 23.8 multiplied by 10 ^-4 ×h ₁ ，

Axial deformation σ of the screw 102 _L Is 11.5X 10 ^-4 ×L；

In addition, the axial deformation σ of the insulating sleeve 103 _h3 Is about h ₃ And 80, the insulating sleeve 103 is made of polyethylene terephthalate (PET) added with 35-55% of glass fibers or polyphenylene sulfide (PPS) added with 35-55% of glass fibers, and the pressure born by the single insulating sleeve 103 is about 15 kN.

So as to obtain the required actual deformation x which is more than or equal to x delta t + sigma _h3 +σ _L -σ _h1 Wherein Δ t is the deformation of the single disc spring when not considered to be heated.

The gasket 104 is sleeved on the insulating tube and located at two ends of the disc spring group 101, and the gasket 104 has good extensibility and can play a role in buffering, so that the service life of the disc spring group 101 is prolonged.

Alternatively, the first heat sink 50 and the second heat sink 70 of the present embodiment are fixedly connected by four insulating fasteners 10. The conventional thyristor element mounting structure includes at least one thyristor element, wherein each thyristor element is connected to the first heat sink 50 and the second heat sink 70 on both sides thereof using two conventional insulating fasteners 10, and thus it is necessary to provide a leveling device such as a steel ball or the like. The leveling device is not beneficial to reducing the number of parts and the size and weight of the thyristor element assembly structure. In the embodiment, since each thyristor element is connected to the first heat sink 50 and the second heat sink 70 on both sides thereof by using four insulating fasteners 10, even if a leveling device is not used, a height difference caused by tolerance of each component can be eliminated, thereby ensuring uniform pressure distribution.

As shown in fig. 9 to 11, alternatively, the insulating sleeve 103 of the present embodiment is a one-piece sleeve, and the insulating sleeve 103 includes a first tube and a second tube which are communicated with each other, the first tube has a larger diameter than the second tube, the first tube is used for accommodating a head of the screw 102, and the second tube is used for accommodating a part of a main body of the screw 102 and extends from the first heat sink 50 to the second heat sink 70.

The integral bushing facilitates improved voltage withstand rating and mechanical withstand voltage performance of the insulated fastener 10. Soft starters employing an integral bushing can withstand voltages up to 6500 v.

Alternatively, the insulating sleeve 103 of the present embodiment includes a first tube and a second tube separated from each other, the first tube is located between the main body of the screw 102 and the first heat sink 50, and the second tube is located between the main body of the screw 102 and the second heat sink 70.

The first tube body and the second tube body which are separated from each other are beneficial to reducing production and installation costs, but the soft starter adopting the first tube body and the second tube body which are separated from each other can only be suitable for voltages below 1800 v. When the voltage is higher than 1800v, it cannot be safely used.

Alternatively, the insulating sleeve 103 of the present embodiment is made of a material having a relative tracking index of 400 or less, thereby being advantageous in ensuring safe use of the thyristor element assembly structure.

As shown in fig. 9 and 12, alternatively, the thyristor element assembly structure of the present embodiment includes two antiparallel thyristor elements and two first heat sinks 50, the first heat sinks 50 corresponding to the thyristor elements one to one.

The thyristor element mounting structure of the present embodiment includes two antiparallel thyristor elements, and a circuit topology thereof is shown in fig. 14. As shown in fig. 9, the two first radiators 50 of the present embodiment are integrated. In the prior art, when the two first heat sinks 50 are separated from each other, in order to realize the anti-parallel topology of the thyristor element, connecting copper bars are also needed to connect the two first heat sinks 50 in series. As a whole, two first radiators 50 have undertaken the effect of connecting two thyristor components, need not to use external copper bar to connect, can reduce material cost and reduce thyristor component assembly structure's volume, are favorable to soft starter's miniaturization to improve soft starter's market competition.

As shown in fig. 9, alternatively, the two first heat sinks 50 of the present embodiment form an integral heat sink with the stress dividing groove 5011 opened therebetween.

Due to the limitations of machining accuracy and cost, two thyristor components, in particular two thyristor components from different production batches, may have a height difference. Meanwhile, the contact plane between the heat sink and the thyristor element cannot be absolutely flat, and the height of the heat sink cannot be consistent. The sum of the heights of the thyristor element and its heat sink on both sides cannot be kept consistent, typically with a 20-50 μm difference.

When the press presses the assembled structure of the thyristor device to be fixed, the vertical downward pressing stress may interfere due to the height difference, and in order to avoid the pressure interference and thus improve the life span of the product, a stress separation groove 5011 is provided between the two first heat sinks 50. The press is pressed and fixed to ensure that the electrical contact between the layers of the thyristor component assembly is good.

As shown in fig. 9, optionally, the first heat sink 50 of the present embodiment includes a first base 501 and a plurality of first fins 502, and a stress separation groove 5011 is provided between the two first bases 501; the second heat sink 70 includes a second base 701 and a plurality of second fins 702.

The size of the stress separation groove 5011 corresponding to different pressures under different working conditions is 1.5-4.0mm, and the thickness of the first substrate 501 after cutting is 2-30 mm. The two first heat sinks 50 with the stress separation slots 5011 as a whole can still withstand the short-term overcurrent of 1000 and 7500A.

The fins may improve the heat dissipation capability of the heat sink by increasing the surface area. As shown in fig. 9, the first fin 502 needs to be disposed avoiding the stress separation slot 5011 and the insulating fastener 10.

Optionally, in order to further optimize the heat dissipation capability of the first heat sink 50 and the second heat sink 70, simulation analysis may be performed according to the power level of the thyristor element to determine the specific sizes of the substrate and the fins, such as the number of fins, the length-to-height ratio of the fins, the size of the fins, and the size of the substrate.

The embodiment also provides a soft starter which comprises the thyristor element assembling structure.

As shown in fig. 12 and 13, a first end of the lead wire 20 of the soft starter is fixedly connected to the gate electrode assembly 80, and a second end of the lead wire 20 is fixed with a standard plug connector to connect the gate electrode assembly 80 and the trigger control board of the soft starter through the lead wire 20, wherein fig. 13 is a partially enlarged view showing a specific structure of the plug connector.

The soft starter of this embodiment has adopted the thyristor component assembly structure of the last thyristor component that has, need not to adopt the welding, and lead wire 20 also need not to run through the lateral wall of chip package subassembly 60, is favorable to improving soft starter's life, also is favorable to reducing soft starter's production and use cost, and is favorable to soft starter's miniaturization to be favorable to this soft starter to obtain market acceptance.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims

1. A thyristor element comprising a gate assembly and a die package having a blind hole at least partially fixedly engaged with the gate assembly, the blind hole having an axis perpendicular to a die in the die package, the gate assembly comprising:

a gate pin extending from the interior of the gate assembly and having a bottom abutting a chip gate of the chip; the gate pole needle comprises a needle body and an elastic part which are integrally formed, and the needle body abuts against the chip gate pole;

a lug plate extending out of the top of the second gate piece for connecting the gate needle and the lead; the first end of the lug is embedded into the elastic piece and is used for being connected with the gate pole needle, the second end of the lug extends out of the top of the second gate pole piece, and the second end of the lug is provided with a through hole for fixing the lead;

the first gate pole piece is penetrated by the needle body to abut against the chip gate pole; and the number of the first and second groups,

the second gate pole piece is sleeved outside the first gate pole piece and fixedly jointed in the blind hole of the chip packaging assembly so as to fixedly joint the gate pole assembly and the chip packaging assembly;

the chip packaging assembly comprises a first packaging shell and a second packaging shell, the first packaging shell and the second packaging shell enclose to form a packaging cavity, and an anode molybdenum sheet, the chip, a cathode molybdenum sheet and a silver gasket are sequentially superposed in the packaging cavity, wherein the anode molybdenum sheet is in contact with the first packaging shell, and the silver gasket is in contact with the second packaging shell; the gate needle penetrates through the silver gasket and the through hole on the cathode molybdenum sheet to abut against the gate of the chip;

the first packaging shell comprises an anode copper block and an anode plastic shell surrounding the anode copper block, the second packaging shell comprises a cathode copper block and a cathode plastic shell surrounding the cathode copper block, and the blind hole is formed in the middle of the cathode copper block.

2. A thyristor element according to claim 1, wherein the outer wall of the second gate member is at least partially threaded with the side wall of the blind hole in the chip package assembly.

3. The thyristor element defined in claim 1, wherein the second gate member is in interference fit with the first gate member to form a cavity for receiving the spring in compression, and the lug extends through the second gate member and is connected to the gate pin.

4. Thyristor element according to claim 3, characterized in that the diameter of the cavity is 0.1-0.3mm larger than the diameter of the spring.

5. The thyristor element defined in claim 1, wherein the blind hole is located in a middle portion of the chip package assembly.

6. The thyristor element defined in claim 1, wherein the first and second package housings are each formed using a metal insert molding process.

7. The thyristor device of claim 1, wherein the chip package assembly encapsulates the chip with a solid sealing medium, and the first package housing defines a glue injection opening.

8. Thyristor element according to claim 7, characterized in that the solid sealing medium is silicon gel.

9. A thyristor component according to claim 8, wherein the silica gel, when in the liquid state, has a viscosity of between 500 and 800 mpa.s; after the silica gel is cured, the dielectric strength of the silica gel is 12 kV/mm.

10. A thyristor component assembly structure comprising a first heat sink, a second heat sink and a thyristor component as claimed in any one of claims 1 to 9 sandwiched between the first heat sink and the second heat sink.

11. A thyristor component assembly structure according to claim 10, wherein the first heat sink and the second heat sink are fixedly connected by four insulating fasteners comprising:

the screw rod penetrates through the first radiator and is in threaded fit with the threaded hole of the second radiator;

the insulating sleeve is sleeved on the screw rod;

the disc spring group is sleeved outside the insulating sleeve and positioned between the first radiator and the insulating sleeve;

and the gasket is sleeved on the insulating sleeve and arranged at two ends of the disc spring group.

12. A thyristor component assembly structure according to claim 11, wherein the insulating sleeve is a one-piece sleeve comprising a first tubular body and a second tubular body communicating with each other, the first tubular body having a larger diameter than the second tubular body, the first tubular body being adapted to receive a head of the screw, the second tubular body being adapted to receive part of a body of the screw and extending from the first heat sink to the second heat sink.

13. A thyristor component assembly structure according to claim 11, wherein the insulating sleeve comprises a first body and a second body that are separate from each other, the first body being located between the main body of the screw and the first heat sink, the second body being located between the main body of the screw and the second heat sink.

14. A thyristor element assembly structure according to claim 11, wherein the insulating sleeve is made of a material having a relative tracking index of less than or equal to 400.

15. A thyristor element assembly structure according to claim 10 or 11, comprising two anti-parallel thyristor elements and two first heat sinks, the first heat sinks corresponding one-to-one to the thyristor elements.

16. A thyristor component assembly structure according to claim 15, wherein the two first heat sinks form an integral heat sink with a stress splitter slot therebetween.

17. A thyristor component assembly structure according to claim 16, wherein the first heat sink comprises a first base and a plurality of first fins, the stress splitter groove being provided between the two first bases; the second heat sink includes a second base and a plurality of second fins.

18. A soft starter comprising a thyristor element assembly according to any one of claims 10 to 17.